A key feature of our architecture is that it promises full scalability to a large number of qubits, as required for fault tolerance.
Working in one temporal and two spatial dimensions ensures that each mode traverses a path of constant optical depth that is independent of the number of qubits in the computer.
This is in contrast to existing schemes for CV computation, where increasing the numbers of qubits requires either longer time delays [1]}, [2]}, longer measurement integration times, or more precise spectral resolution [3]}, [4]}.
Such an increase will tend to result in exponentially growing losses so these architectures cannot be scaled indefinitely.
Moreover, the components of our architecture can be arranged as a planar graph: each qubit is connected only to a small and constant number of neighboring qubits and the layout of the computational chip consequently requires no `swaps' or intersecting wave-guides.
This planar structure not only opens the possibility of scalable fabrication but also allows for preserving the local structure of the noise.
An uncorrelated noise structure like the one enabled by our architecture is critical as it allows exploiting the full machinery of fault-tolerance.
